Disazo dyestuff and process of making same.



RUDOLF SCI-I'U'LE, 0F FRANKFORT-ON-THE-MAIN, GERMANY.

DISAZO DYESTUFF AND PROCESS OF MAKING SAME.

No Drawing.

I have discovered that by combining the diazocompound obtained from diazo-p-nitrobenzene and aminocresolalkylether (CH :NH :OR l :3 :4)

where R denotes an alkyl group and further diazotation with m-aminophenyl-S-oxy-LQ. naphthimidazole-3.6-disulfonic acid in alkaline solution, a disazodyestuff is obtained which dyes cotton bluish black shades; these may be developed on the fiber, yielding bril- Specification of Letters Patent.

Patented Sept. 25, 191?.

Application filed March 20, 1916. Serial N 0. 85,506.

liant green shades by further diazotizing and developing with l-phenyl-3-methyl-5-pyrazolone, phenol, cresol or resorcinol. Brilliant green shades are likewise obtained by aftertreatment with p-nitrodiazobenzene. The developed dyeings are of good fastness to washing, soap and light.

The process is illustrated by the following example:

The diazocompound obtained from 13.8 kilos p-nitranilin, 35 kilos hydrochloric acid and 6.9 kilos sodium nitrite is allowed to run into a solution of 13.7 kilos aminocresolmethylether with 11.5 kilos hydrochloric acid cooled down to 0 C. by the addition of ice. The formation of the aminoazocompound is complete after about 4 hours standing. It is further diazotized by the addition of about 11.5 kilos hydrochloric acid and 6.9 kilos sodium nitrite, and then allowed to run into a solution of 43.5 kilosxn-aminophenyl-8- oXy-1.2-naphthimidazole-3.6-disulfonic acid rendered alkaline with sodium carbonate. The dyestuff is salted out from the warmed solution by means of common salt, and filtered off. It has the following structural formula:

The dyestufi dissolves in water with a bluish black color, in concentrated sulfuric acid with a green color. The bluish black shades on cotton are turned into a brilliant green by developing with phenylmethylpyrazolone, into a green shade by developing with resorcinol, phenol or 0-, m-, and pcresol.

By aftertreatment with p-nitrodiazobenzene, brilliant green shades are obtained.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare, that what I claim is 1. The process of producing a new disazodyestuff which consists in diazotizing the aminoazo'compound obtained from the diazo derivative of p-nitroanilin and aminocresolalkylether and combining the diazoazocompound thus formed in an alkaline solution with m-aminophenyl-b-oxy-LQ-naphthimidazole-3.6-disulfonic acid, the dyestuff thus obtained dyeing cotton bluish black shades which are turned into green shades by diazotizing on the fiber and developing with 1- phenyl-3-methyl-5-pyrazolone, phenol, cresol or resorcinol, and also by aftertreatment with the diazo derivative of p-nitroanilin, substantially as described.

2. The herein described new disazodyestuff obtained by combining the diazocompound of p -nitrobenzeneazoaminocresolmethylether in alkaline solution with m aminophenyl-8-oxy-L2-naphthimidazole-3.6- disulfonic acid, the said disazodyestuif being a dark powder soluble in water with a and yielding by treatment with stannous chlorid p-phenylenediamin, diaminocresol- 10 methylether and m-aminonheny1-7-amino-8- oxy-1.2-naphthimidazo1e-3.6-disulfonic acid, substantially as described.

In witness whereof I have hereunto signed my name this day of February 1916, in the presence of twosubscribing witnesses. 15

Dn. RUDOLF soHULE.

Witnesses CARL GRUND, JEAN GRUND. 

